<template>
  <el-container class="home-container">
    <!-- 头部区域 -->
    <el-header>
      <div>
        <!-- 黑马logo -->
        <img src="../assets/heima.png"
             alt="">
        <!-- 顶部标题 -->
        <span>电商后台管理系统</span>
      </div>
      <el-button type="info"
                 @click="logout"> 退出 </el-button>

    </el-header>

    <!-- 页面主体区域 -->
    <el-container>
      <!-- 侧边栏 -->
      <el-aside :width="isCollapse ? '64px' : '200px'">
        <div class="toggle-button"
             @click="toggleCollapse">|||</div>
        <!-- 侧边栏菜单区域 -->

        <!-- unique-opened，是否只保持一个子菜单的展开 -->
        <!-- isCollapse 是否水平折叠收起菜单 -->
        <!-- collapse-transition，是否开启折叠动画 -->
        <!-- router 启用该模式会在激活导航时以 index 作为 path 进行路由跳转 -->
        <!-- default-active，当前激活菜单的 index -->
        <el-menu background-color="#545c64"
                 text-color="#fff"
                 active-text-color="#ffd04b"
                 :unique-opened="true"
                 :collapse="isCollapse"
                 :collapse-transition="false"
                 :router="true"
                 :default-active="activePath">
          <el-submenu :index="item.id + ''"
                      v-for="item in menuList"
                      :key="item.id">
            <!-- 一级菜单模板 -->
            <template slot="title">
              <!-- 图标 -->
              <i :class="iconsObj[item.id]"></i>
              <!-- 文本 -->
              <span>{{item.authName}}</span>
            </template>
            <!-- 二级子菜单 -->
            <el-menu-item :index="'/' + subItem.path"
                          v-for="subItem in item.children"
                          :key="subItem.id"
                          @click="saveNavState('/' + subItem.path)">
              <!-- 二级菜单模板 -->
              <template slot="title">
                <!-- 图标 -->
                <i class="el-icon-menu"></i>
                <!-- 文本 -->
                <span>{{subItem.authName}}</span>
              </template>
            </el-menu-item>
          </el-submenu>
        </el-menu>
      </el-aside>
      <el-main>
        <!-- 路由占位符 -->
        <router-view>

        </router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {
  data () {
    return {
      // 左侧菜单数据
      menuList: null,
      iconsObj: {
        125: 'iconfont icon-user',
        103: 'iconfont icon-tijikongjian',
        101: 'iconfont icon-shangpin',
        102: 'iconfont icon-danju',
        145: 'iconfont icon-baobiao'
      },
      // 是否折叠
      isCollapse: false,
      activePath: ''
    }
  },

  // created:在模板渲染成html前调用
  created () {
    this.getMenuList()
    this.activePath = window.sessionStorage.getItem('activePath')
  },

  methods: {
    logout () {
      window.sessionStorage.clear()
      this.$router.push('/login')
    },
    // 获取所有的菜单,并赋值给data中数据
    async getMenuList () {
      // 发送请求获取左侧菜单数据
      const { data: res } = await this.$http.get('menus')
      if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
      this.menuList = res.data
      // console.log(res)
    },
    // 点击按钮，切换菜单的折叠与展开
    toggleCollapse () {
      this.isCollapse = !this.isCollapse
    },
    // 保存链接的激活状态--菜单高亮
    saveNavState (activePath) {
      window.sessionStorage.setItem('activePath', activePath)
      this.activePath = activePath
    }
  }
}
</script>

<style lang="less" scoped>
.home-container {
  height: 100%;
}

.el-header {
  background-color: #373d41;
  // 弹性布局，display: flex; 将布局分散在两边 justify-content: space-between;
  display: flex;
  justify-content: space-between;

  padding-left: 0;
  align-items: center; // 字体居中
  color: #fff; // 字体颜色
  font-size: 20px;
  > div {
    display: flex;
    align-items: center;
    span {
      margin-left: 15px;
    }
  }
}

.el-aside {
  background-color: #333744;
  .el-menu {
    border-right: 0;
  }
}

.el-main {
  background-color: #eaedf1;
}

.iconfont {
  margin-right: 10px;
}

.toggle-button {
  background-color: #4a5064;
  font-size: 10px;
  line-height: 24px;
  color: #fff;
  text-align: center;
  letter-spacing: 0.2em; // 字体间距
  cursor: pointer; // 鼠标悬停变成小手
}
</style>
